Fix minor typo in git rename-branch man page

[danpaolella]

Show the option as <old-branch> and <new-branch> instead of <old-branch> and <new-branch>.

[spacewander]

This file is generated with https://github.com/tj/git-extras/blob/main/man/Readme.md#description.
Better to fix in the original source or the generator.

[danpaolella]

My bad I missed that, sorry.
I took a peak at the ronn rabbit hole and couldn't make it run on my system yet, I'll need more time on it, or investigate the options in #831.

[spacewander]

That's fine.

[danpaolella]

I eventually managed to run ronn and generate the doc files, here I added a few notes in case it's useful to somebody else.

I'd like to ask:

1. I added a new commit as per guidelines, would you like me to remove the previous revision for a cleaner history?
2. I re-formatted the source file for consistency with the other rename commands docs, but the rename-file options are rendered as a definition list in the HTML: would you like me to adjust the rename docs (and perhaps other commands), to have their options turned into DLs too?

[spacewander]

I added a new commit as per guidelines, would you like me to remove the previous revision for a cleaner history?

It's fine. We will squash it in the merge.

I re-formatted the source file for consistency with the other rename commands docs, but the rename-file options are rendered as a definition list in the HTML: would you like me to adjust the rename docs (and perhaps other commands), to have their options turned into DLs too?

I would recommend doing it in a separate PR.

[danpaolella]

I would recommend doing it in a separate PR.

Agreed, thank you!

[spacewander]

@danpaolella
Merged. Thanks!